Perturbations of Equatorial Satellites Due to Equatorial Ellipticity.

by Richard H. Frick


Purchase Print Copy

 FormatList Price Price
Add to Cart Paperback36 pages $20.00 $16.00 20% Web Discount

An examination of the ellipticity of the earth's equatorial section that causes appreciable perturbations in the motion of a synchronous satellite relative to the earth. This memorandum extends the analysis to include circular equatorial orbits other than synchronous. It is found that the only orbits other than synchronous that are appreciably perturbed by ellipticity are those with 12- and 36-hour periods. The resulting perturbation is a divergent oscillation in both orbital radius and orbital angular position. Actually, the rate of divergence is very slow, and, as a result, the major station-keeping problem is still the steady-state drift in angular position resulting from residual errors in initial orbital radius and orbital velocity. The earth's equatorial ellipticity provides no stabilization to orbital rate that could be used for station-keeping contrary to the recent proposal on "Natural Station-Keeping" by the ROSAE Corporation

This report is part of the RAND Corporation Research memorandum series. The Research Memorandum was a product of the RAND Corporation from 1948 to 1973 that represented working papers meant to report current results of RAND research to appropriate audiences.

Our mission to help improve policy and decisionmaking through research and analysis is enabled through our core values of quality and objectivity and our unwavering commitment to the highest level of integrity and ethical behavior. To help ensure our research and analysis are rigorous, objective, and nonpartisan, we subject our research publications to a robust and exacting quality-assurance process; avoid both the appearance and reality of financial and other conflicts of interest through staff training, project screening, and a policy of mandatory disclosure; and pursue transparency in our research engagements through our commitment to the open publication of our research findings and recommendations, disclosure of the source of funding of published research, and policies to ensure intellectual independence. For more information, visit

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.